Protection of acetylene lines



J. L. ANDERSON PROTECTION OF ACETYLENE LINES July 17, 1928.

Filed Sept. 24, 1.924

Patented July 17, 1928.

UNITED STATES PATENT'OFFICE.

JAMES L. ANDERSON, OF ENGLEWOOD, NEW COMPANY, INCORPORATED, OF NEW YORK,

JERSEY, assrenoa TO AIR REDUCTION N. Y., a ooaroaarron on NEW YORK.

rnorncrron or ACETYLENE LINES.

Application filed September 24, 1924. Serial No. 739,472.

In shops and factories where oxyacetylene welding and cutting torchesare employed, using acetylene from generators, the permanent acetylenelines leading from the generator, and to which the torches are connectedat various points by flexible hose, are more or, less susceptible torupture with danger of serious consequences.

In order to protect the generator from disturbances arising from faultyoperation or misuse of the torches, a deep water-seal havring a checkvalve is interposed in the line at a strategic point, so that backpressure and flame will be prevented from passing the point, the flamebeing extinguished by the water ofthe seal. The part of the line betweenthe water-seal and the torches is nevertheless subject to an excess ofinternal.

pressure, which may be of either one of two the torch does not orders.Usually,.a backfire or flashback in go beyond the mixing chamber of thetorch, but at times, if the torch nozzle happens to be obstructed, itmay be carried back intothe acetylene line by a higher oxygen pressure.Then, if it continues to burn quietly at the point where the oxygen andacetylene meet, and is not extinguished at the water-seal, the pressurein the line-rises at a certain rate and requires to be relieved. Thecombustion reaction may also develop into an explosive reaction,

causing a large and instantaneous increase in pressure; or an explosivemixture introduced into the hne in some manner from one of the torchesand carried unburned, it may be to a point in the system far removedfrom its source, may subsequently become ignited by the attempt of someone to operate his torch. .Such ail-explosion may tear apart the line,with escape of-flame and gas, and it may also, in spite of barriers,drive back to the generator, where grave damage has been caused.

The apparatus herein described is designed to arrest and extinguishdisturbances. before they can reach the generator, and at the same timeto vent the gas chamber of the water seal and the affected part of theline to the atmosphere. important art of the invention the way to theatmosp ere may be openedthrough one or both of two paths or ranches,functionally in parallel relatio the particular functioning depending uon the nature and force of the disturbance. Both branches are nor-According to an mally closed, one branch being closed by an closed by adisk adapted to burst at excessive pressure.

A further feature. of the invention relates to means enabling thewater-seal to be charged with water without the entrance of air.

In the accompanying drawings forming part hereof:

Fig. 1 is an elevation, partly in vertical section, and with theintermediate part of the vent pipe broken out, of a water-sealandsuperstructure embodying the invention, adjacent portions of the gasline being. shown;

Fig. 2 is a view on a larger scale, partly in section and partly inelevation, of the superstructure and the upper part of the watersealchamber; and

Fig. 3 is a cross-section on the line 33 of Flg. 1.

The enclosure of the water-seal illustrated in these views is formed bya tight vertical tank 2 of strong construction, having-a removablebolted cover.3 sealed by a gasket 4.

The inlet part of the acetylene line, coming from the generator, ismarked 5 this partof the line, by suitable fittings, being connected toand passing downward through an opening in the cover and having theextension 6 which descends to near-the bottom of the water chamberformed by the lower half of the tank more or less, andterminates in anupturned exit 7. This exit, dis osed Well below the water-level,is-guarded y an automatic check-valve 8 arranged to 0 en to pressurefrom the generator side 5, ut to close against back pressure gas seekingentrance through the exit 7.

The water level of the seal, marked a, is established by a fillingentrance and pipe in conjunction-with an overflow pipeand exit. Thefilling and overflow openings are in the side of the tank approximatelymid! way of the height, and are closed by removable plugs 9 and 10respectively. Both the filling and the overflow pipes 11 and 12connected with these openings extend far down within the tank, so thattheir lower ends are much below the water-1evel,and as indicated atleast as low as the gas exit 7 In this way the water body can bereplenished from time to time without possibility of air getting in toform a combustible or explosive mixture with the acetylene.

In another opening in the cover 3, and communicating with the gas outletchamber formed by the upper part of the tank, is a fitting 13, fromwhich extends the service side 14 of the acetylene line.

The fitting 13 is also the support and entrance limb for asuperstructure, marked generally 15, which divides into two parallelbranches 16 and 17, joined above to a vent pipe 18 extending upward todischarge above the roof of the building. The roof line is re resentedby the horizontal line at the top 0 Fig. 1.

The branch 17 disposed in straight line with the entrance limb 13 fromthe gas outlet chamber of the water-seal and preferably also in directline with the chimney 18, contains a frangible disk 19 bolted betweenflanges 20. A spider 21 in the enlarged chamber 22 above this disk isdesigned to keep pieces of the disk, when ruptured, from clogging of theoutlet pipe 14.

The-other branch 16 is shown carried off laterally from the entrancelimb from a second tee fitting 23, below the frangible disk, and turnedupward by an elbow, to rejoin the first branch by a lateral nipple andanother tee fitting 24 above the disk at the base of the vent pipe.Naturally, the specific construction may be varied.

The branch 16 contains at a suitable point, preferably at its uppercorner, a valve-chamber 25 containing an annular valve-seat 26 and anormally seated valve member 27 adapted to move bodily away from itsseat in response to'a definite ressure in the water-seal and line 14. Tis valve, which is illustrated as of a known type, is loaded by anadjustable spring 28, which, under all normal conditions, holds thevalve closed, but permits it to yield when the predetermined pressureexists.

Thus, if the system carries an acetylene gas pressure of 15 lbs. to thesquare inch, which is customary, the relief valve will be loaded to openat a pressure somewhat above this value, for example at a pressure of 18lbs. This will vent the seal and line under the less emergent abnormalconditions which may occur from time to time, and which need not callfor ashut-down or for repairs. In event of a true explosion, or in caseof the valve 27 not functioning for any reason, the disk 19 will giveaway, and save the system. It is best that this disk be calc'ulated towithstand a comparatively high pressure, but to yield certainly andcompletely at a pressure such as to protect the permanent system fromrupture or injury. This pressure may be in the neighborhood of 50 lbs.per square inch, but it will be understood that figures are given by wayof illustration. In case of an explosion the instantaneous force of thereaction is delivered directly against the disk, shattering it, and atthe same time the valve 27 is forced open, so that two avenues of escapeare afforded.

Excess gas back pressure or blow, whether due to a, flashback combustionor an explosion, will be kept from the generator by the check-valve 8,and even should this valve fail, the direct and double vent from theseal to the atmosphere insures the generator against injury from thiscause. Actual flame will be extinguished by the water body of the seal,at the time that one or both vent passages open so as to prevent anypossibility of the flame being blown back to the generator, as forinstance should thelre be a leaky or insufficiently charged sea What Iclaim:

1. A safety apparatus for acetylene gas lines comprisin in combinationwith the line, a water-sea having a gas inlet and an outlet chamber, anda superstructure in free communication with the outlet chamber of thewater-seal, said superstructure comprising two normally-closed branchesin parallel by one or both of which excess pressure may open an escapeto atmosphere, one of said branches containin a loaded mechanical reliefvalve adapte to open at a pressure somewhat above the normal of the lineconnected with said outlet chamber, and the other branch being closed bya frangible disk calculated to yield to excessive pressure.

2. A safety apparatus for acetylene gas lines comprising in combinationwith the line, a water-seal having a gas inlet and an outlet chamber, acover for the chamber, and a superstructure having a limb openingthrough said cover, a service line conduit connected with said limb, avent pipe, and two normally-closed relief branches interposed betweensaid limb and line conduit on the one hand and the vent pipe on theother hand, one of said branches containing a loaded mechanical reliefvalve and the other branch being closed by a frangible disk.

3. A safety apparatus for acetylene gas lines comprising in combinationwith the line, a water-seal having a gas inlet and an outlet chamber,and a superstructure in free communication with the outlet chamber ofthe water-seal, said superstructure comprising two normally-closedbranches in parallel by one or both of which excess pressure may open anescape to atmosphere, one of said branches containing a loadedmechanical relief valve and the other branch being closed by a frangibledisk, the branch containing said disk being in straight linecommunication with the outlet chamber of the waterseal.

4. A safety apparatus for acetylene gas lines comprising in combinationwith the line, a water-seal having a gas inlet and an outlet chamber,and a superstructure in free communication with the outlet chamber ofthe Water-seal. said superstructure comprising two normally-closedbranches in parallel by one or both of which excess pressure may open anescape to atmosphere, one of said branches containing a loadedmechanical relief valve and the other branch being closed by a frangibledisk, the branch containing said disk being in straight linecommunication With the outlet chamber of the waterseal, while the branchcontaining the relief valve is carried off laterally from the straightbranch and then extended upwardly to a junction therewith above thedisk, and a vent pipe extending from the junction.

JAMES L. ANDERSON.

